The fragile build of this enormous harvestman belies its deadliness. An exclusive dweller of the island's bamboo forests, mother longlegs are spending most of their time standing motionlessly, their bodies elevated above the canopy and their legs nearly invisible between the stalks. Like most arachnids, they have poor vision and orient themselves mostly by touch and by sensing vibrations. They can precisely locate moving entities that pass by, impaling suitable prey with their long tibial spurs. Despite their size, mother longlegs are pretty weak animals, unable to get up again if their bodies are brought down on the ground. Instead of picking prey up with their grasping pedipalps they instead employ their modified, prehensile ovipositor to drag it up, then hold it in their pedipalps while tearing it apart with their chelicerae. Mother longlegs are one of the few inhabitants of Skull Island that regularly prey on skullcrawlers.
They are parthenogenous and produce a lot of small eggs that are buried in the soil. Young mother longlegs are quite different from the adults, being pretty agile predators with shorter legs and longer pedipalp spines. Instead of waiting for prey to pass by and stab them with tibial spurs, the juveniles are active nocturnal hunters that grab and subdue their food with their pedipalps instead. The subadult stage is remarkable for having a type of snorkel on its back; this organ is essential for the final molt, which happens in a body of water to support the animal's weight until the exoskeleton is hardened and allows the adult to walk out in its typical erect posture.

The one I was most eager to redesign. Sorry for the poor quality, I just suck at drawing long, thin objects. The scientific name is a reference to an European harvestman genus, Megabunus.

Changelog:
-MOTHERFUCKING DAGGERFEET. Why why whyyyy to creature designers think having pointy feet on arthropods is a good thing? I know there are actual arthropods with dagger feet, but those are either very small (springtails), don't support much of their weight on their legs (larvae) or are aquatic (crustaceans). An animal this size walking around on soft soil would result in the legs either getting stuck or breaking off, which are both sucky outcomes (and walking on hard ground would wear the tips down very fast and pose a danger for breaking the legs, too). Therefore, proper feet with wide claws to prevent sinking into the soil while the pointy bits for impaling soldiers through their piehole is located on the tibiae.
-Rather than having tentacles on their abdomen (wtf) that drag prey directly into the stomach (double wtf) they now have a prehensile ovipositor to pick things up and bring them to the chelicerae, where the food is stuffed into the actual mouth. Well, that might also explain why they have no males, because prehensile harvestman penis might be too NSFW for a movie where people get shredded by helicopters, having their limbs ripped off or creatures get their eyes shot out by flares and get disemboweled through their mouths.
-Instead of having horizontally oriented pincers they now have vertically oriented pedipalps as found in Laniatores harvestmen https://c1.staticflickr.com/4/3796/.....29b6feb3_b.jpg Having them oriented vertically is pretty important if you live in an environment with a lot of vertically oriented bamboo stalks.
-A proper harvestman body without a pedicel and proper harvestman eyes (which means two of them, in black and not composite).
-No plant parts, as they are not necessary.